Report reveals the effect of a changing climate on Scotland’s birds

The distribution, numbers and behaviour of many birds in Scotland is changing due to a changing climate.

·Many of our rare breeding birds found in Scotland are at a high risk of extinction, based on projections of how climate will become less suitable for these species

·Climate change will provide opportunities for some species while others will be more vulnerable

·Migratory birds are arriving in the UK earlier each spring and leaving later each autumn

The distribution, numbers and behaviour of birds in the UK, including many in Scotland, are changing because of a changing climate according to a new report.

The State of the UK’s Birds 2017 (SUKB) - the one-stop shop for all the latest results from bird surveys and monitoring studies – this year highlights how many of the UK’s species across the four countries, are already being affected by climate change, responding to UK average summer temperatures having increased by nearly 1 degree Centigrade since the 1980s.

The report highlights how species are moving northwards within the UK, shifting their distributions as temperatures rise and the habitats change. Many of our rarer breeding birds are at a high risk of extinction in the UK, based on projections of how climate will become less suitable for these species. For species such as the dotterel, whimbrel, common scoter and snow bunting, whose UK breeding populations are found almost entirely in Scotland, population declines have been considerable already.

Breeding success of the Slavonian grebe has also been impacted. With Scotland on average 11 per cent wetter between 2007-2016 than 1961-1990 periods of very heavy rainfall during its breeding season leads to smaller populations.

The reports also shows that the Scottish crossbill, the UK’s only endemic bird and only found in Scotland, is at risk of becoming extinct.

However, the report contains better news for some birds which are finding the changed climatic conditions more favourable in Scotland. Nuthatch, goldfinch and chiffchaff have been expanding their range into Scotland over the last 30 years with large increases in the number of these birds breeding here. While the UK cuckoo population has declined by 43 per cent between 1995 and 2015, over the same period numbers in Scotland have increased by a third. Similar patterns have also been noted in numbers of willow warbler, house martins and tree pipits in Scotland.

Dr David Douglas, Principal Conservation Scientist at RSPB Scotland said: “The recent research compiled in this year’s The State of the UK’s Birds report shows that many birds in Scotland are being affected by a changing climate. For some birds this means they are becoming increasingly vulnerable to UK extinction, including many species where most, if not all, of the breeding population is found in Scotland. Other birds appear to have thrived in this warmer, wetter climate, which has allowed them to expand their range further north. Some species which were previously unusual visitors to Scotland now breed here in considerable numbers.”

One of the most compelling revelations is how birds have adapted their behaviour in response to warming temperatures.

One of our most familiar summer visitors, the swallow, which migrates to and from southern Africa each year, is arriving back in the in the UK 15 days earlier and breeding 11 days earlier than it did in the 1960s. Swallows and other migratory birds, such as garden warblers and whitethroats are also delaying their return migration each autumn and so some species are now spending up to 4 weeks longer in the UK each year.

But it isn’t only our migrant birds that are changing their behaviour. One of our most familiar resident garden birds, the great tit is also laying its eggs 11 days earlier than 40 years ago. These are obvious and major changes that show that even our common wildlife is already being affected by climate change.

Dr Stuart Newson, Senior Research Ecologist at the British Trust for Ornithology (BTO) and lead author of the migration research highlighted in the report, said “Thanks to thousands of volunteers, many of whom have submitted observations to us over many decades, we have been able to show how birds like cuckoo and house martin have responded to a changing climate. The information provided has enabled us to see that some of our summer visitors are now arriving over 20 days earlier that they did in the 60s.”

Colette Hall, monitoring officer at WWT, said: “It isn’t just our breeding birds that are responding to the changing climate. Each winter, tens of thousands of waterbirds migrate to the UK and our long running network of volunteer waterbird counters has tracked their changes over decades. Warmer winters on the continent have meant more birds of certain species wintering further east, such as the European White-fronted Goose. However, that trend can mask real declines in some species, such as the Bewick’s swan and the common pochard. For this reason, amongst many others, it is vital we continue to monitor our bird populations so we can pinpoint where, and subsequently try to work out why, these changes are happening. We also need to think beyond the UK and make sure that the protected site network continues to cover the right places throughout Europe and that they’re monitored elsewhere as thoroughly as they are in the UK.”

The SUKB 2017 is produced by a coalition of three NGOs: the Royal Society for the Protection of Birds (RSPB), the British Trust for Ornithology (BTO) and the Wildfowl & Wetlands Trust (WWT), together with the UK’s statutory nature conservation bodies: Department of Agriculture, Environment and Rural Affairs, Northern Ireland (DAERA), the Joint Nature Conservation Committee (JNCC), Natural England (NE) and Natural Resources Wales (NRW).